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Australia Pacific LNG Project Volume 3: Gas Pipeline Chapter 22: Hazard and Risk

Volume 3: Gas Pipeline Chapter 22: Hazard and Risk

Australia Pacific LNG Project EIS March 2010 Page ii

Contents

22. Hazard and risk .................................................................................................................. 1

22.1 Introduction.................................................................................................................... 1

22.1.1 Purpose ................................................................................................................. 1

22.1.2 Scope of work........................................................................................................ 2

22.1.3 Legislative framework............................................................................................ 2

22.2 Methodology .................................................................................................................. 7

22.3 Hazard and risk assessment ......................................................................................... 7

22.3.1 CSG properties and potential hazards.................................................................. 7

22.3.2 CSG release and fire types ................................................................................... 7

22.3.3 Hazardous substances.......................................................................................... 8

22.4 Gas pipeline hazards and risks ..................................................................................... 9

22.4.1 Plant and equipment ........................................................................................... 10

22.4.2 Natural hazards ................................................................................................... 17

22.4.3 Vehicles and traffic .............................................................................................. 21

22.4.4 Cumulative risk levels to surrounding land uses................................................. 24

22.4.5 Consequence assessment overview................................................................... 24

22.4.6 Gas pipeline hazard scenarios............................................................................ 25

22.4.7 Consequence assessment summary .................................................................. 29

22.5 Safety management study........................................................................................... 30

22.6 Health and safety......................................................................................................... 34

22.6.1 Community health and safety.............................................................................. 34

22.6.2 Health and safety of persons onsite during construction .................................... 35

22.6.3 Health and safety of persons onsite during operations....................................... 40

22.6.4 Mitigation and management................................................................................ 42

22.7 Emergency management ............................................................................................ 42

22.7.1 Contents of the emergency response plan ......................................................... 43

22.8 Conclusion................................................................................................................... 46

22.8.1 Assessment outcomes ........................................................................................ 46

22.8.2 Commitments ...................................................................................................... 47

References ...................................................................................................................................... 48


Australia Pacific LNG Project EIS March 2010 Page iii

Figures

Figure 22.1 Whole of life gas pipeline safety management (AS 2885.1) ............................................. 12

Tables

Table 22.1 Proposed gas pipeline diameters and lengths ..................................................................... 9

Table 22.2 Maximum credible release requirements ........................................................................... 11

Table 22.3 Potential gas pipeline construction hazards....................................................................... 13

Table 22.4 Potential operation and maintenance hazards................................................................... 15

Table 22.5 Potential decommissioning hazards................................................................................... 17

Table 22.6 Potential hazards related to natural disasters .................................................................... 18

Table 22.7 Potential vehicle and traffic hazards .................................................................................. 22

Table 22.8 Summary of consequence assessment for gas pipeline.................................................... 29

Table 22.9 Physical and procedural controls for external interference protection ............................... 31

Table 22.10 Potential workplace health and safety risks during construction...................................... 38


Australia Pacific LNG Project EIS March 2010 Page 1

22. Hazard and risk

22.1 Introduction

22.1.1 Purpose

This chapter of the environmental impact statement (EIS) identifies the potential hazards and risks associated with the design, construction, operation, maintenance and decommissioning of the main gas transmission pipeline (the gas pipeline), and discusses measures to mitigate any of the identified potential impacts.

Coal seam gas (CSG) will be transported from the gas fields to the liquefied natural gas (LNG) facility on Curtis Island near Gladstone via a buried high pressure gas pipeline approximately 450km long. Details of the proposed gas pipeline design, route and construction methods are presented in Volume 3 Chapter 3.

This chapter is largely based on Marsh Pty Ltd's studies and technical report in Volume 5 Attachment 46. Australia Pacific LNG has also undertaken a preliminary safety management study of the gas pipeline system in accordance with Australian Standard AS 2885.1: Pipelines – Gas and liquid petroleum. A summary of the findings of the preliminary safety management study is provided in Volume 5 Attachment 49 for the gas pipeline system.

The process of identifying hazards and risks has involved the following:

• Background research on the properties and characteristics of CSG

• Review of industry experience of pipeline incidents

• Hazard identification workshops specific to the Project

• Review of risks identified within Origin's existing risk registers relevant to the Project.

Hazards were identified and a risk register prepared. The hazards, which are based on abnormal events, natural hazards or accidents are summarised in this chapter. Hazards and risks are presented in four main sections:

• Section 22.3 outlines the potentially dangerous goods and hazardous substances associated with the Project

• Section 22.4 outlines the risks to the surrounding environment, based on Marsh's technical reports. This includes a consequence analysis of hazards considered to represent significant consequences in the area of the gas pipeline

• Section 22.5 outlines the hazards and risks based on the preliminarily safety management study

• Section 22.6 outlines risks to health and safety.

The potential hazards and risks associated with the gas fields are discussed in Volume 2, and those associated with the LNG facility are discussed in Volume 4. An overall summary of the risk assessment process is presented in Volume 1 Chapter 4.

Australia Pacific LNG's key sustainability principles will be applied to the planning, design, construction, operation, maintenance and decommissioning of the gas pipeline to ensure associated hazards and risks do not aversely impact people or the environment.



Of the 12 Australia Pacific LNG sustainability principles, the following are most relevant to the gas pipeline hazard and risk component of the EIS:

• Adhering to an overriding duty to safety, ensuring operations are carried out in a safe manner and empowering employees and contractors to place safety considerations above all other priorities

• Minimising adverse environmental impacts and enhancing environmental benefits associated with Australia Pacific LNG's activities, products or services; conserving, protecting, and enhancing where the opportunity exists, the biodiversity values and water resources in its operational areas

• Identifying, assessing, managing, monitoring and reviewing risks to Australia Pacific LNG's workforce, its property, the environment and the communities affected by its activities.

The ultimate objective is to design, construct and operate the gas pipeline in such a manner as to ensure a minimal impact on the surrounding environment and community, with no substantial residual risk to public amenity and ensuring the safety of those in proximity to the gas pipeline and associated facilities. The strategies outlined in this EIS will demonstrate how these sustainability principles will be addressed.

22.1.2 Scope of work

A preliminary assessment of the hazards and risks associated with the gas pipeline, from the gas processing facilities to the LNG facility on Curtis Island, has been conducted and distances to hazard end points have been estimated. This is part of an ongoing process that will see the hazards and risks assessed throughout the life of the Project. Hazard and risk assessments will be conducted for the design, construction, commissioning, operations and decommissioning stages, and these hazards and risks will also be reviewed at regular intervals throughout the life of the Project. A detailed safety management study of the gas pipeline will be conducted in the detailed design stage.

Management strategies are presented, which reduce the risks to as low as reasonably practicable, low or negligible. The broad aim of Australia Pacific LNG is to avoid risk whenever it is practical to do so.

This chapter addresses general process hazards and risks and major accident events. Hazards and risks related to air emissions including odours and greenhouse gases, dust, noise and vibration, water quality, soil including acid sulfate soil, wastes, and societal hazards and risks are included in other chapters of this EIS. The relevant chapters describe the related hazards and outline controls to reduce the risk. For example, air emissions are further discussed in Volume 3 Chapter 13.

22.1.3 Legislative framework

Queensland legislation

Volume 1 Chapter 2 provides an overview of the general regulatory framework as it applies to the entire project. While current legislation is outlined in the following sections, the Project will be undertaken in accordance with the legislative requirements in force over the course of the Project. Legislation relevant to potential hazards and risks associated with the gas pipeline is listed below. The relevance of these to the Project is then explained.



Petroleum and Gas (Production and Safety) Act

The Petroleum and Gas (Production and Safety) Act 2004 (PAG Act) regulates petroleum and natural gas in Queensland. It aims to facilitate and regulate the carrying out of responsible petroleum activities and the development of a safe, efficient and viable petroleum and fuel gas industry.

Petroleum activities include:

• Exploration, distillation, production, processing, refining, storage and transport of petroleum

• Distillation, production, processing, refining, storage and transport of fuel gas

• Other activities authorised under the Act for petroleum authorities.

One facet of the Act is to achieve this in a way that minimises land use conflicts and encourages responsible land use management.

The safety obligations contained in the Act apply to an operating plant as defined in the Act. Specifically, the Act mandates the application of AS 2885 (discussed below), and so this Australian Standard becomes a legislative requirement under this Act.

Dangerous Goods Safety Management Act

The Dangerous Goods Safety Management Act 2001 sets out the obligations and requirements relating to the storage and handling of dangerous goods and combustible liquids, and the safe operation of major hazard facilities in Queensland. Dangerous goods are defined with reference to the 'Australian Code for the transport of dangerous goods by road and rail'.

The Dangerous Goods Safety Management Regulation 2001 sets out specific obligations for people who manufacture, import, supply, store or handle stated dangerous goods or combustible liquids, or who supply or install equipment for storing or handling those materials.

The Act and regulation are concerned with protecting against harm or injury to people or damage to property or the environment arising from an explosion, fire, harmful reaction or the evolution of flammable, corrosive or toxic vapours involving dangerous goods; or the escape, spillage or leakage of any dangerous goods. They also define the criteria by which a facility will be classified as a 'large dangerous goods location' or a 'major hazard facility'. Additional risk minimisation requirements are defined for such facilities so the necessary licenses must be obtained to operate.

However, certain parts of the Act and regulations do not apply to:

• Land that under the PAG Act is used to obtain, produce or transport petroleum

• Pipes under the PAG Act (other than pipes within the boundaries of a major hazard facility or large dangerous goods location).

Therefore, the gas pipeline is not considered a major hazard facility and will be primarily governed by the PAG Act. Major hazard facilities are administered by the Hazardous Industries and Chemicals Branch within the Department of Justice and the Attorney-General, whilst the gas fields and gas pipeline will be administered by the Queensland Mines and Energy branch of the Department of Employment, Economic Development and Innovation. The Project will obtain the necessary licenses and authorities to operate under the PAG Act.



Explosives Act

The Explosives Act 1999 provides for the regulation of explosives, including approval to manufacture, possess, sell, store, transport or use explosives in order to ensure the safety of the community from all activities associated with explosives.

For example, if explosives are required for blasting along gas pipeline routes, a licence or approval under this Act will be required for the purchase, transportation and use of explosives.

Radiation Safety Act

The Radiation Safety Act 1999 provides for the regulation of radioactive substances. There could be radioactive sources used for weld testing or other purposes. Australia Pacific LNG will ensure radioactive source users have the required licence and an approved radiation safety and protection plan, detailing radiation protection measures.

Workplace Health and Safety Act

The Workplace Health and Safety Act 1995 establishes a framework for preventing or minimising workers' exposure to risks by, among other things, imposing safety obligations on certain persons and establishing benchmarks for industry through the making of regulations and codes of practice. The Act does not apply to operating plant, within the meaning of the PAG Act on land the subject of a petroleum authority under the PAG Act or petroleum tenure under the Petroleum Act 1923.

The Workplace Health and Safety Act will apply for most construction activities.

Coal Mining Safety and Health Act

The Coal Mining Safety and Health Act 1999 regulates the operation of coal mines, to protect the safety and health of persons at coal mines and persons who may be affected at coal mining operations. These objects are achieved by, among other things, imposing safety and health obligations on certain persons and providing for safety and health management systems.

The Coal Mining Safety and Health Act 1999 may be relevant to the Project to the extent that any exploration, construction, extraction, processing or treatment of CSG occurs on a coal mining lease or in an area contiguous, adjoining or adjacent to a coal mining lease. With respect to this, the gas pipeline passes through the Callide Coalfields.

Fire and Rescue Service Act and Fire and Rescue Service Regulation

The Fire and Rescue Service Act 1990 and Fire and Rescue Service Regulation 2001 requires the operator to establish effective relationships with the Queensland Fire and Rescue Service to provide for the prevention of and response to fires and certain other incidents endangering persons, property or the environment and/or for related purposes or activities.

Relevant state planning policies

Various state planning policies may be relevant to the development of the gas pipeline. The following two policies have particular relevance to the hazard and risk section of the gas pipeline element of the Project:

State Planning Policy 1/03 Mitigating the Adverse Impacts of Flood, Bushfire and Landslide

This policy requires that developments should minimize the potential adverse impacts of flood, bushfire and landslide on people, property, economic activity and the environment. The policy has



effect when development applications are assessed, when planning schemes are made or amended and when land is designated for community infrastructure.

State Planning Policy 2/02, Planning and Managing Development Involving Acid Sulfate Soils

This policy will apply during the construction phase of the gas pipeline for the low-lying land at Gladstone, due to the potential impact on the environment. The effects of acid sulfate generation from such soil disturbance also has the potential to increase corrosion of the gas pipeline.

Whilst development of the gas pipeline is exempt from assessment under local government authority planning schemes, Australia Pacific LNG will apply the principles and objectives set out in relevant State Planning Policies to the design, construction and operation of the gas pipeline.

Relevant national and international standards

The key standards that apply to hazard and risk assessment for the Project are outlined below.

AS 2885: Pipelines - Gas and liquid petroleum

AS 2885 refers to a set of Australian Standards concerning gas and liquid petroleum pipelines which are relevant to the Project's gas pipelines. This is the primary Australian Standard to be used as a basis for the design, construction and operation of the Project's gas pipelines. Part 1 of this standard, AS 2885.1-2007: Pipelines - Gas and liquid petroleum - Design and construction, defines the requirements for the design and construction of gas pipelines.

Key requirements of AS 2885 limit the consequence and likelihood of off-site impacts and these requirements will be implemented as part of the Project, including:

• Development of a 'fracture control plan', to ensure selection of gas pipeline material which is resistant to brittle or ductile fracture

• Provide a level of resistance to penetration of the gas pipeline to reduce the likelihood of penetration and significantly reduce the likelihood of a full bore rupture

• Prevention of rupture in 'high consequence' class locations

• Maximum tolerable energy release rates – this limits the radiated heat flux generated from a fire.

Guides referred to in AS 2885.1 include SAA HB105-1998 and HIPAP 4 as outlined below.

HB 105-1998: Guide to pipeline risk assessment in accordance with AS 2885.1

This guide forms the basis for the risk assessment of pipelines in accordance with AS 2885.1.

Risk Criteria for Land Use Safety Planning (Hazardous Industry Planning Advisory Paper no. 4)

This advisory paper, referred to as HIPAP No. 4, which is directed in the terms of reference, outlines the consequences of heat flux and overpressure, which are referred to in the 'Guide to pipeline risk assessment in accordance with AS2885.1 1998' produced by Standards Australia and in 'Guidelines for major hazard facilities C Systematic risk assessment 2008' produced by the Queensland Government. The paper and associated consultation draft 'Revised planning guidelines for hazardous development, August 2008' provide risk criteria for land uses in the vicinity of hazardous industries.

AS/NZS ISO 31000:2009: Risk management - Principles and guidelines

This Australian Standard provides a framework for evaluating potential hazards and reducing the risk of those hazards. The associated Risk Management Code of Practice 2007 and its supplements



provide information on how risk management can be achieved. This standard replaces the recently superseded AS 4360: Risk Management.

Other standards

Below is an indicative list of other major standards that will be applicable to the Project. It is recognised that there are other national standards, codes of practice, advisory standards and guidance notes of relevance that are not indicated in this list:

• AS 1170.4-2007: Structural design actions - Earthquake actions in Australia

• AS 1885.1-1990 Workplace Injury and Disease Recording Standard in the Workplace

• AS 2865-1995 Safe Working in a Confined Space (NOHSC:1009(1994))

• AS 2958 Earth Moving Machinery – Safety

• AS 3868-1991 Earth-moving machinery - Design guide for access systems

• AS 4024 Safety of machinery

• AS/NZS 4801:2001: Occupational health and safety management systems - Specification with guidance for use

• AS/NZS 60079.10.1:2009: Explosive atmospheres - Classification of areas - Explosive gas atmospheres (IEC 60079-10-1, Ed.1.0(2008) MOD)

• AS IEC61511:2004: Functional Safety – Safety instrumented systems for the process industry sector

• National Standard for Construction Work [NOHSC: 1016 (2005)]

• National Standard for Manual Tasks (2007)

• National Standard for Occupational Noise [NOHSC: 1007 (2000)]

• National Standard for Plant [NOHSC: 1010 (1994)]

• Australian Code for the Transport of Dangerous Goods by Road and Rail, 7th Edition

• Australian Code for the Transport of Explosives by Road and Rail, 3rd Edition

• National Code of Practice for the Control of Workplace Hazardous Substances [NOHSC: 2007 (1994)]

• National Code Of Practice for Induction for Construction Work, May 2007

• National Code of Practice for the Prevention of Falls in General Construction, April 2008

• The National Code of Practice for the Prevention of Musculoskeletal Disorders from Performing Manual Tasks at Work (2007)

• National Code of Practice for the Prevention of Occupational Overuse Syndrome [NOHSC:2013(1994)]

• Mobile Crane Code of Practice 2006

• Plant Code of Practice 2005

• Risk Management Code of Practice 2007



• Traffic Management for Construction or Maintenance Work Code of Practice 2008.

22.2 Methodology

Australia Pacific LNG, through Origin Energy, has a system of risk management which uses the concepts based on AS/NZS ISO 3100:2009: Risk management - Principles and guidelines. Risk management is considered as the systematic and ongoing process of hazard identification, assessment, treatment and monitoring.

The risk management methodology used by Australia Pacific LNG in undertaking the risk assessment for the EIS stage of the Project is outlined in Volume 1 Chapter 4.

22.3 Hazard and risk assessment

Australia Pacific LNG will design the gas pipeline so that it is inherently safe. Risk assessment is considered an important part of this process. Australia Pacific LNG will use risk assessments throughout the life of the Project to capture and treat the various hazards and risks associated with its activities.

Origin has been operating gas pipelines for a number of years. This has allowed them to develop and accumulate fairly extensive risk registers for the construction, operation and decommissioning of existing gas pipelines. These provide a good initial basis for evaluating the potential hazards and risks the Project will introduce. Potential hazards range from bites from venomous snakes through to hazards from construction of, and operating and maintaining, industrial plant and equipment.

Hazards were identified through a review of Origin's existing risk registers, with a reference to initial designs and a review of related industry hazards. Scenarios were then developed to establish credible events that could conceivably impact persons, property or the environment. Where hazards were significant and quantifiable, distances to hazard end points were determined. The overall gas pipeline hazard and risk assessment and the preliminary safety management study have been completed in accordance with the requirements of the Australian Standard for gas and liquid petroleum pipelines (AS 2885).

22.3.1 CSG properties and potential hazards

Analysis of the CSG from the Walloons gas fields shows that the methane content is greater than 97%. Methane is an odourless, non-toxic and non-corrosive gas and is lighter than air above minus 110oC. The lower and upper flammability limits of methane are 5% and 15% respectively. This means if the concentration of methane in air is less than 5%, the gas mixture is too dilute to burn and if it is greater than 15% there is not enough oxygen for it to burn. The auto-ignition point for methane is 580oC. This is the minimum temperature required to ignite the gas in air without a spark or flame being present.

Methane is also an asphyxiant. Asphyxia begins to be significant if the oxygen concentration is reduced to below 19.5%.

Methane is compressible and a release of high pressure methane will result in localised low temperatures due to expansion cooling (Joule – Thompson effect).

22.3.2 CSG release and fire types

When CSG is released there will not necessarily be a fire. The potential outcomes are:



• Gas release without a fire

• Immediate ignition and fire

• Delayed ignition resulting in a flash fire, or vapour cloud explosion if in a confined area, and resultant jet fire.

Note that boiling liquid expanding vapour explosion and pool fires are not considered in this section of the EIS, as there will not be any liquefied CSG or other liquefied hydrocarbons in the gas pipeline element of the Project.

A gas release will not result in a fire if the gas is not exposed to an ignition source.

If an ignition source is present near the release point a fire could occur. If a release of CSG occurs at low pressure and low velocity, any resultant fire would resemble standard combustion. A methane flame is typically quite difficult to see in daylight conditions. A release of CSG ignited and under pressure would result in a 'jet fire'. A jet fire has the shape of a cone.

If a gas release does not ignite immediately, a gas cloud may form which could find an ignition source distant from the point of release. A flash fire or vapour cloud explosion may occur under these circumstances. A flash fire is the term for a slow deflagration of a premixed, truly unconfined, unobstructed gas cloud producing negligible overpressure. Thermal effects are the main hazard.

A vapour cloud explosion is an explosion occurring with the release of a large quantity of flammable gas, which ignites following the formation of a cloud or plume of pre-mixed fuel and air. For a vapour cloud to explode, there is a minimum and maximum ratio of fuel vapour to air within which ignition can occur. This range is 5 to 15% for methane. It is unlikely that there would be enough confined gas in a cloud in the given ratios in a confined space for a vapour cloud explosion to occur. For gas that could ignite, it has a greater prospect of combustion via a flash fire mechanism, which generally does not create a damaging pressure wave and thus a vapour cloud explosion is unlikely to occur.

22.3.3 Hazardous substances

CSG is itself considered a hazardous substance. CSG, consisting predominantly of methane, is a flammable gas and asphyxiant as described in Section 22.3.1. Other potentially hazardous substances are described below.

Before CSG is transmitted through the pipeline and during decommissioning, the gas pipeline may potentially be purged with nitrogen. Nitrogen is a colourless, odourless and tasteless gas that comprises approximately 78% of the Earth's atmosphere. There have been a number of fatalities in Australia, Canada and the United States from accidental nitrogen asphyxiation in the mining industry. Only reputable and experienced nitrogen purging contractors will be utilised. Enclosed spaces will be minimised, leaks will be monitored and remedial action taken, during commissioning and decommissioning to ensure this risk does not eventuate.

Typical material used for gas pipeline construction consists of:

• Line pipe – steel

• Consumables (welding rods, grinding discs, and so on)

• External coating and field joint coating materials

• Sand bags or polystyrene foam blocks

• Slag or garnet for sand blasting pipes



• Markers, post and signs

• Fuels and lubricants

• Fencing.

There will be no substantial use or storage of hazardous substances related to gas pipeline operations and there is unlikely to be a substantial use or storage of hazardous substances during construction. Fuels and lubricants will be used as a part of vehicle transport and equipment maintenance and are unlikely to be stored near the gas pipelines.

Any chemicals, including fuels and lubricants, are likely to be in smaller quantities, and will be managed using material safety data sheets and dangerous goods guidelines.

22.4 Gas pipeline hazards and risks

The major hazards identified for the gas pipeline are presented in the following sections. For each risk, the potential hazard, the possible causes, the foreseeable consequences and key controls are presented in tables. These tables are based on numerous risk workshops conducted during the EIS studies, which included relevant experts and experienced personnel.

There is some overlap between the risks for the gas fields (Volume 2) and gas pipeline (Volume 3). Potential hazards and risks are described for the drilling, construction, operation and decommissioning phases within the following areas:

• Plant and equipment – gas pipeline

• Natural hazards

• Vehicles and traffic.

The gas pipeline is considered to begin at the pig launcher at the beginning of the pipeline, which includes the Woleebee and Condabri lateral pipelines, and is considered to end at the pig receiver where it joins Australia Pacific LNG's proposed LNG facility near Laird Point. The gas pipeline consists of three sections which are summarised in Table 22.1.

The high pressure gas pipeline network from the outlet of each gas processing facility to the start of the laterals is at essentially the same pressure and presents similar hazards to the gas pipeline, which is the subject of this volume of the EIS. For further information about the hazards and risks of this pipeline network refer to Volume 2 Chapter 22.

Table 22.1 Proposed gas pipeline diameters and lengths

Section Nominal diameter of pipe (inches) Length of pipeline (km)

Main pipeline 42 362

Condabri lateral 36 44

Woleebee lateral 30 38

The construction of the gas pipeline will include establishment of temporary accommodation facilities and laydown areas. Vehicle transport to and from the accommodation facilities, pipelines, major towns, airports and rail stations will be required. Vehicles, such as light vehicles, excavators, trenching machines and diggers will be utilised for gas pipeline construction. The gas pipeline will be underground with the pipeline surfacing at 'scraper stations' along the route. The gas pipeline will



cross several roads, whose amenity will be maintained during the construction and operation phases of the Project, these include Warrego Highway, Eidsvold to Theodore Road and Dawson Highway.

The gas pipeline will be constructed by trenching, boring under roads, and horizontal directional drilling (HDD). Intermittent scraper stations allow the insertion and retrieval of devices known as 'pigs' to internally clean and inspect the pipe. Australia Pacific LNG proposes to use 'intelligent pigs', which collect various forms of data, such as pipeline wall thickness and profile. A supervisory, control and data acquisition system will be installed and used to monitor and control the gas flows. The gas pipeline will be patrolled both aerially and on the ground. The pipes will have an external coating and impressed current cathodic protection to reduce the risk of corrosion. The pipes will be welded and non-destructive testing will be undertaken on the welds to check the weld integrity.

22.4.1 Plant and equipment

Gas pipeline design and whole of l ife safety management

Many of the potential hazards and risks in the construction and operation of the gas pipeline will be taken into consideration in the design of the gas pipeline. The design features will prevent many of the potential hazards from occurring or reduce the damage that could occur.

The design and construction of the gas transmission system will be based on AS 2885, which covers the gas pipeline itself and associated equipment, such as compressor and meter stations. The objectives and fundamental principles of the standard include:

• Safety of the general public and pipeline personnel

• Protection of the environment

• Security of supply.

To comply with AS 2885:

• Australia Pacific LNG will be responsible for the safety of the gas pipeline.

• All threats to a gas pipeline will be identified and either controlled or the associated risks will be evaluated and managed to an acceptable level

• The gas pipeline will be designed and constructed to have sufficient strength, ductility and toughness to withstand all design loads to which it may be subjected during construction, testing and operation. The design will be reviewed, assessed and approved

• Before the gas pipeline is placed into operation, it will be inspected and tested to prove its integrity

• The integrity and safe operation of the gas pipeline will be maintained in accordance with an approved safety and operating plan

• Where changes occur in or to a gas pipeline or its surroundings, which alter the design basis or affect the original integrity, appropriate steps will be taken to assess the changes and where necessary implement modifications to maintain safe operation of the gas pipeline.

• At the end of its system design life, the gas pipeline will be abandoned unless an approved engineering investigation determines that its continued operation is safe

• Before a gas pipeline is abandoned, an abandonment plan will be developed and approved.



Australia Pacific LNG will develop and maintain a safety management plan incorporating a whole of life safety management approach, which will include risk management, safety management studies, construction safety management plans, safety and operating plans, safety audits and reviews as indicated in which will meet AS 2885 and PAG Act requirements.

In accordance with AS 2885, the principal gas pipeline safety design requirements are determined according to different location classifications, which are based on the nature and population density of adjacent land uses. Minimum standards are specified for protection of the gas pipeline against failure, and for limitation of the potential consequences of a failure at these different location classifications. The standard also requires that the gas pipeline be designed to limit the maximum credible release for certain location types. The gas pipeline design will comply with the maximum credible release requirements outlined in AS 2885 in any given location. For example, the maximum credible release rate will be limited to 10 gigajoules per second when the gas pipeline is in a location considered residential, industrial or sensitive. This is described in Table 22.2.

Table 22.2 Maximum credible release requirements

Location class Maximum credible release rate (gigajoules per second)

Residential

Industrial

Sensitive (e.g. hospitals, aged care, schools)

10

High density residential 1

Figure 22.1 from AS 2885 shows a whole-of-life gas pipeline safety management approach. Australia Pacific LNG will use this approach and manage each part of the life of the gas pipeline from preliminary design to abandonment. The stated studies, management and safety plans will be developed at each stage over the life of the gas pipeline.



Figure 22.1 Whole of life gas pipeline safety management (AS 2885.1)

Gas pipeline construction

The majority of the gas pipeline will be constructed by open-cut trenching and backfill. Thrust boring will be used to cross roads, railways and other infrastructure and HDD will be used to for the marine crossing of The Narrows at Port Curtis. The potential risks that may arise during the construction phase and which could impact the wider community are outlined in Table 22.3.



Health and safety risks to workers onsite, such as risks associated with manual handling and falling pipe, are further outlined in Section 22.6.

Australia Pacific LNG will employ reputable contractors for the construction of the gas pipeline, and will work with them to develop construction procedures for the entire operation. This will include areas that will need to be barricaded, vehicle management plans, assessment of the location and height of powerlines and design of the gas pipeline.

Table 22.3 Potential gas pipeline construction hazards

Potential hazard

Possible causes Possible consequences

Proposed controls Residual risk level

Damage to infrastructure during construction

Excavation

Use of explosives

Vehicle impact

Interruption to community or business

Injury or death

Identification of infrastructure

Surveys

Controlled use of explosives by trained and licensed contractors

Vehicle management plan

Reputable pipeline construction contractors

Construction safety management plans

Low

Person, fauna or vehicle falling into open excavations or trenches

Unexpected open excavations

Damage to vehicles

Injury or fatality

Loss of fauna

Boring of pipeline at road crossings

Construction safety management plan

Environmental management plan

Barricades

Identification

Low

Overhead electrical transmission power line damaged

Boring and trenching operations

Pipeline construction equipment operated by or transported under power lines and interfering/ making contact with live lines

Mechanical impact

Interruption to power

Electrocution and /or fatality

Standard operating procedures for boring and trenching

Gas pipeline route

Height of transmission powerlines

Potential use of isolation devices

Low

Damage to data cables

Excavation

Use of explosives

Loss of service

Electrocution and/or fatality

Standard operating procedures for explosives

Dial before you dig (or use explosives)

Low



Potential hazard



Uncontrolled detonation of explosives

Fire or spark as an ignition source leading to detonation

Misfire

Premature detonation

Overcharge

Radar in close proximity (airport)

Fatality or serious injury

Potential rupture of adjacent gas pipeline

Explosion

Qualified explosives operator

Exclusion zone and radio silence or shielded fuses whilst undertaking explosive operations

Low

Accommodation fire

Electrical fault

Naked flame

Hot oil

Source of fuel and ignition

Kitchen fire

Loss of infrastructure

Injury or death

Smoke detectors installed and operational

Fire fighting equipment installed and operational

Emergency response procedures

Ongoing education and training of persons

Low

Infrastructure collapse

Design failure

Deliberate damage or sabotage

Maintenance oversight

Equipment damage

Damaged pipeline

Fatality or injury

Infrastructure designed to standards

Hazard and risk identification throughout the project

Liaison with authorities


Standard operating procedure for explosives

Exclusion of persons from construction sites

Low

Exposure to radiation

Radioactive sources used for instrumentation e.g. x-ray for pipeline integrity

Time near source and distance from source

Radiation source is dropped or lost

Radiation sickness

Non-destructive testing personnel are licensed according to the Radiation Safety Act 1999

Reputable weld testing service acquired

Negligible



Gas pipeline operation and maintenance

Some of the potential hazards involved in the operation and maintenance of the gas pipeline are outlined in Table 22.4. Australia Pacific LNG will undertake maintenance and conduct inspections for the commissioning, operation and decommissioning of the gas pipeline to prevent such risks. Procedures will include the steps for normal operation, pigging, corrosion, isolation and repairs. Specific procedures will be developed for emergency situations. Prior to commissioning, a full commissioning plan and a safety and operating plan will be developed, and maintenance and inspections persons will be fully trained in these procedures.

Australia Pacific LNG will conduct regular training sessions and undertake regular auditing and integrity inspections. Auditing and integrity inspections will be conducted for the gas pipeline (as per AS 2885.1) and for associated infrastructure. Auditing will also include compliance with standards, operating and safety procedures. The safety plan will be regularly reviewed and updated based on feedback, which will be proactively obtained. Other controls will include:

• Traffic management

• Consultation with the local community

• Signage and identification of buried pipe

• Safety, operational, inspection and maintenance procedures

• Ongoing training and education of site personnel

• Environmental management plans.

With the implementation of these controls the risks during operations and maintenance will be negligible or low.

Table 22.4 Potential operation and maintenance hazards

Potential hazard



Slow leak Hole in gas pipeline

Corrosion (corrosion escalated by acid sulfate soils)

Asphyxiation

Loss of gas

See below Negligible

Gas pipeline rupture - buried

Excavation

Earthquake

Corrosion

Dredging through The Narrows

Jet flame fire or flash fire

Injury or fatality

Selection and placement of gas pipeline easement

Design standards for potential earthquake loads

Gas pipeline designed to prevent full bore rupture

Depth of cover

Gas pipeline markers and signage

Leak detection from operating parameters or other means

Low



Potential hazard



Regular pigging

Remote monitoring of pressure and flow

Remotely operated isolation at mid line valves

Corrosion inhibitor and cathodic protection


Gas pipeline rupture - surface

Mechanical failure of pipe / flanges / valves (such as caused by corrosion)

Damage from vehicle collisions

Mechanical impact

Earthquake

External interference

Bushfire


Injury or fatality



Quality assurance of installed equipment

Inspection and condition monitoring program

Secured area around aboveground gas pipeline infrastructure


Remotely operated isolation valves


Low

Rupture of adjacent gas pipeline

Use of explosives during construction

Excavation or drilling

Earthquake

Australia Pacific LNG gas pipeline rupture

Dredging


Injury or fatality

Gas pipeline survey to ensure separation distance

Controlled use of explosives by trained and licensed contractors


See above

Negligible

Underwater gas leak from pipeline through The Narrows

Mechanical failure

Corrosion

Earthquake

Dredging through The Narrows

Flammable gas cloud and flash fire

Impact on marine environment

Quality assurance of installed equipment



Corrosion inhibitor and cathodic protection

Negligible



Potential hazard



Depth of cover


Remotely operated isolation valves


Decommissioning hazards

Gas pipeline decommissioning involves the pigging, flushing, filling, and plugging of each line, followed by abandonment in place. Rehabilitation of land will be undertaken where necessary, such as revegetation. Potential hazards associated with decommissioning are outlined in Table 22.5. The potential hazards involved in decommissioning will be further assessed closer to the decommissioning date, as techniques and requirements are likely to change. Initiatives will potentially include an abandonment plan, environment plan, maintenance plan and safety assessment.

Table 22.5 Potential decommissioning hazards

Potential hazard Possible causes Possible consequences


Gas pipeline gas explosion during decommissioning

Unpurged gas pipeline and introduction of hot work

Corrosion leakage with introduction of hot work

Explosion

Injury and fatality

Decommissioning safety plan

Purging of gas pipeline

Assessment of corrosion

Pigging before purging

Low

22.4.2 Natural hazards

Natural disasters

Potential hazards related to natural disasters are presented in Table 22.6. The likelihood of any damage in the event of a natural disaster will be significantly reduced through the design of the gas pipeline and associated equipment and facilities. Emergency response plans will be developed for at least the following scenarios and adhered to in any disaster and these will include procedures for evacuation of personnel, containment of equipment and protection of the environment. The controls that will be in place will reduce the risk to acceptable levels.

Note that climate and climate change is further discussed in Volume 3 Chapter 4 and that emergency response plans are included in Section 22.7.

Volu

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Tabl

e 22

.6 P

oten

tial h

azar

ds re

late

d to

nat

ural

dis

aste

rs

Pote

ntia

l haz

ard

Poss

ible

cau

ses

Poss

ible

con

sequ

ence

s Pr

opos

ed c

ontr

ols

Res

idua

l ris

k le

vel

Geo

logy

and

geo

mor

phol

ogy

Ea

rthqu

ake

Land

slid

e

Subs

iden

ce

Gas

pip

elin

e ru

ptur

e

Prop

erty

and

equ

ipm

ent d

amag

e

Env

ironm

enta

l har

m

Inju

ry to

per

son

Des

ign

of g

as p

ipel

ine

to w

ithst

and

such

ev

ents

Loca

tion

of g

as p

ipel

ine

away

from

vu

lner

able

are

as

Ong

oing

mon

itorin

g an

d in

spec

tions

of g

as

pipe

line

Emer

genc

y re

spon

se p

lans

Neg

ligib

le

Sto

rms

Win

d

Rai

n

Dus

t

Equi

pmen

t dam

age

Inju

ry to

per

sons

Obs

erve

wea

ther

fore

cast

s, w

arni

ngs

and

upda

tes

from

the

Bur

eau

of M

eteo

rolo

gy

Emer

genc

y re

spon

se p

lans

Low

Cyc

lone

s Se

ason

al a

nd w

eath

er

rela

ted

Dam

age

to v

ehic

les

and

equi

pmen

t

Inju

ry o

r dea

th o

f peo

ple

Obs

erve

wea

ther

fore

cast

s, w

arni

ngs

and

upda

tes

from

the

Bur

eau

of M

eteo

rolo

gy

Des

ign

of e

quip

men

t for

sto

rm e

vent

s

Emer

genc

y re

spon

se p

lans

Bur

ied

gas

pipe

line

Low

Floo

ds

Exce

ssiv

e ra

in

Riv

er fl

ows

Sco

ur a

nd e

rosi

on (l

oss

of v

eget

atio

n an

d so

il)

Loss

of g

as p

ipel

ine

inte

grity

Dam

age

to e

quip

men

t and

veh

icle

s

Obs

erve

wea

ther

fore

cast

s, w

arni

ngs

and

upda

tes

from

the

Bur

eau

of M

eteo

rolo

gy

durin

g co

nstru

ctio

n ph

ase

Emer

genc

y re

spon

se p

lans

Neg

ligib

le

Volu

me

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ipel

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19

Pote

ntia

l haz

ard

Poss

ible

cau

ses

Poss

ible

con

sequ

ence

s Pr

opos

ed c

ontr

ols

Res

idua

l ris

k le

vel

Hea

lth a

nd s

afet

y ris

ks to

peo

ple

Dro

wni

ng

Avo

idin

g re

mot

e lo

catio

ns d

urin

g he

avy

wea

ther

Trav

el m

anag

emen

t

Bur

ial o

f gas

pip

elin

e an

d re

inst

atem

ent o

f w

ater

cou

rse

cros

sing

to a

void

was

h aw

ay

Ligh

tnin

g S

torm

wea

ther

Ligh

tnin

g at

tract

ors

Dam

age

to e

quip

men

t or f

acili

ties

Inju

ry o

r dea

th o

f peo

ple

Obs

erve

wea

ther

fore

cast

s, w

arni

ngs

and

upda

tes

from

the

Bur

eau

of M

eteo

rolo

gy

Ligh

tnin

g pr

otec

tion

for a

t ris

k st

ruct

ures

Ces

satio

n of

cer

tain

act

iviti

es d

urin

g lig

htni

ng, e

.g. e

xplo

sive

act

iviti

es, s

tand

ing

near

/und

er a

ttrac

tors

Emer

genc

y re

spon

se p

lans

Neg

ligib

le

Hea

t wav

e H

igh

tem

pera

ture

s

Clim

ate

chan

ge

Equi

pmen

t dam

age

Hea

t stre

ss o

r dea

th o

f vul

nera

ble

pers

ons

Can

cer f

rom

sun

exp

osur

e

Educ

atio

n an

d tra

inin

g

Man

agem

ent o

f per

sons

Hea

t stre

ss e

mer

genc

y re

spon

se

proc

edur

es

Des

ign

of e

quip

men

t and

util

ities

for h

igh

tem

pera

ture

s an

d in

crea

sed

dem

ands

Use

of p

erso

nal p

rote

ctio

n eq

uipm

ent,

suns

cree

n an

d sh

ade

Neg

ligib

le

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20

Pote

ntia

l haz

ard

Poss

ible

cau

ses

Poss

ible

con

sequ

ence

s Pr

opos

ed c

ontr

ols

Res

idua

l ris

k le

vel

Bus

hfire

Fr

ictio

n / D

ry m

ater

ial

Sou

rces

of i

gniti

on

Dam

age

to v

ehic

les,

equ

ipm

ent a

nd fa

cilit

ies

Inju

ry o

r dea

th o

f peo

ple

Obs

erve

wea

ther

fore

cast

s, w

arni

ngs

and

upda

tes

from

the

Bur

eau

of M

eteo

rolo

gy

Obs

erva

tion

of to

tal f

ire b

ans

for h

igh

risk

days

/ se

ason

s

Educ

atio

n an

d tra

inin

g

Emer

genc

y re

spon

se p

lans

Bush

fire

brea

ks (m

aint

ain

clea

ranc

e ar

ound

ga

s pi

pelin

e an

d te

mpo

rary

acc

omm

odat

ion

faci

litie

s)

Sm

oke

dete

ctio

n at

the

tem

pora

ry

acco

mm

odat

ion

faci

litie

s

Fire

pre

vent

ion

durin

g co

nstru

ctio

n

Mai

ntai

n co

ntac

t with

and

obt

ain

advi

ce

from

rura

l fire

ser

vice

s

Low



Wildlife and disease vectors

Personnel will be exposed to potentially hazardous wildlife, including snakes and spiders, and disease vectors, such as, mosquitoes, rats and flies in the Project area.

Venomous snakes and spiders are known to inhabit the gas pipeline area. Project personnel will be alerted to the risk of snakes and the areas where they are commonly found, such as in long grass or under rocks. First aid training and treatments will be provided.

Mosquitoes are able to transmit viruses such as dengue fever or Ross River fever. Australia Pacific LNG will control mosquito breeding at any temporary ponds during construction and other water areas. The potential for malaria, which has been eradicated from Australia, and disease vectors for other exotic diseases that might be entertained as a result of migration or climate change will be further assessed, if the risks became credible.

The control of disease vectors, such as, insects and rodents is necessary for the maintenance of health and hygiene in any location. Controls are via items, such as screen doors, hygienic practices, covered waste disposal, sanitation and sewerage systems. Accommodation and office areas will be treated to minimise exposure in these environments. Controls will be monitored for effectiveness, verified by means such as audits and inspections or, where appropriate, microbiological sampling of environment and food contact surfaces will be undertaken. These controls will be regularly reviewed and adapted to reflect changed circumstances.

22.4.3 Vehicles and traffic

The potential hazard and risk aspects of road transport and traffic will be managed across the Project through the three elements of road design, vehicle design, and behaviour management of drivers and pedestrians. Potential vehicle and traffic hazards are outlined in Table 22.7. Traffic and transport impacts and their management are further outlined in Volume 3 Chapter 17.

The increase in heavy and light vehicle traffic is considered to have a high residual risk level despite the application of controls to as low as reasonably practicable and the application of controls beyond those required, such as on public roads. Due to the potential fatal consequences of a vehicle accident and the fact that the likelihood related to the background risk of a vehicle accident is high, the residual risk of a vehicle accident to persons and fauna remains high.

Australia Pacific LNG fleet vehicles and hire vehicles used by project personnel will be fitted with an in-vehicle monitoring system. Drivers will be required to comply with a corporate local transport directive, which makes journey planning mandatory.

It is difficult for Australia Pacific LNG to reduce the residual risk further as the designs of public roads and the behaviour of other road users is beyond its control. However, Australia Pacific LNG will actively engage with the relevant authorities to identify particular risks and participate in ongoing campaigns to reduce the likelihood and consequences of vehicle accidents.

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Tabl

e 22

.7 P

oten

tial v

ehic

le a

nd tr

affic

haz

ards

Pote

ntia

l haz

ard

Poss

ible

cau

ses

Poss

ible

con

sequ

ence

s Pr

opos

ed c

ontr

ols

Res

idua

l ris

k le

vel

Incr

ease

d he

avy

and

light

veh

icle

traf

fic

Tran

spor

t of p

ipe

and

othe

r mat

eria

ls

(e.g

. bed

ding

san

d, w

ater

) req

uire

d to

co

nstru

ct th

e ga

s pi

pelin

e

Mov

emen

t of l

arge

num

bers

of

cons

truct

ion

and

oper

atio

n st

aff a

t sh

ift c

hang

es

Add

ition

of h

igh

volu

mes

alo

ng

prev

ious

ly lo

w tr

affic

ked

rout

es

Ele

vate

d ris

k of

ser

ious

or f

atal

m

otor

veh

icle

acc

iden

ts

Incr

ease

d ris

k in

are

as o

utsi

de

of re

gula

r em

erge

ncy

serv

ices

co

ntac

t

Incr

ease

d ris

k of

faun

a in

jurie

s an

d de

aths

Driv

er fa

tigue

mon

itorin

g

Enf

orce

d sp

eed

limits

on

proj

ect v

ehic

les

Use

of b

uses

to m

ove

peop

le -

avoi

d ha

ving

priv

ate

vehi

cles

ons

ite.

Res

trict

ed a

cces

s to

pub

lic to

wor

k ar

eas

Ong

oing

edu

catio

n an

d tra

inin

g of

driv

ers

and

pede

stria

ns in

road

haz

ards

Jour

ney

man

agem

ent p

lan

Veh

icle

s fit

ted

with

in-v

ehic

le m

onito

ring

syst

ems

Con

sulta

tion

with

cou

ncils

and

Dep

artm

ent o

f Tra

nspo

rt an

d M

ain

Roa

ds re

gard

ing

high

risk

inte

rsec

tions

and

se

ctio

ns o

f roa

d

Hig

h

Rai

l and

road

cr

ossi

ngs

Incr

ease

d tra

ffic

at u

ncon

trolle

d cr

ossi

ng

Inju

ries

or fa

talit

ies

Col

lisio

ns a

nd d

isru

ptio

n of

rail

serv

ices

Liai

son

with

cou

ncils

and

Dep

artm

ent o

f Tra

nspo

rt an

d M

ain

Roa

ds in

con

side

ratio

n of

hig

h ris

k ra

il an

d ro

ad

cros

sing

s

Man

dato

ry s

top

at ra

ilway

cro

ssin

gs m

onito

red

by in

-ve

hicl

e m

onito

ring

syst

em

Med

ium

Unc

ontro

lled

deto

natio

n of

ex

plos

ives

Roa

d ac

cide

nt

Det

onat

ors

atta

ched

to s

econ

dary

ex

plos

ives

dur

ing

trans

port

Expl

osio

n (in

clud

ing

over

pres

sure

, deb

ris, h

eat

radi

atio

n an

d no

ise)

Pot

entia

l ser

ious

inju

ry o

r fat

ality

Des

igna

ted

rout

es fo

r the

tran

spor

tatio

n of

dan

gero

us

good

s as

spe

cifie

d in

the

Exp

losi

ves

Act

and

the

Aus

tralia

n C

ode

for t

he T

rans

port

of E

xplo

sive

s by

Roa

d an

d R

ail

Liai

son

with

Em

erge

ncy

Man

agem

ent Q

ueen

slan

d an

d th

e H

azar

dous

Indu

strie

s an

d C

hem

ical

s B

ranc

h re

gard

ing

any

pote

ntia

l han

dlin

g or

sto

rage

of e

xplo

sive

s

Suita

bly

qual

ified

exp

losi

ves

oper

ator

Low

Volu

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23

Pote

ntia

l haz

ard

Poss

ible

cau

ses

Poss

ible

con

sequ

ence

s Pr

opos

ed c

ontr

ols

Res

idua

l ris

k le

vel

Die

sel f

ire in

volv

ing

mob

ile fu

el ta

nker

Ve

hicl

e en

gine

fire

as

an ig

nitio

n so

urce

to th

e fu

el ta

nk

Nak

ed fl

ame

Col

lisio

n

Fire

Env

ironm

enta

l inc

iden

t

Pot

entia

l inj

ury

or fa

talit

y

Suita

bly

qual

ified

fuel

tran

spor

t ope

rato

r (gi

ving

co

nsid

erat

ion

to v

ehic

le m

aint

enan

ce, d

river

trai

ning

and

pr

oced

ures

)

Pro

perti

es o

f die

sel (

diffi

cult

to ig

nite

)

Cle

an u

p pr

oced

ures

as

part

of e

mer

genc

y re

spon

se

plan

Neg

ligib

le

Mar

ine

traffi

c vo

lum

e du

ring

cons

truct

ion

Hig

h vo

lum

e of

mat

eria

ls a

nd p

eopl

e re

quire

tran

spor

t to

Cur

tis Is

land

, in

itial

ly fr

om G

lads

tone

bas

ed

dise

mba

rkat

ion

(Auc

klan

d P

oint

)

Lack

of r

egul

ator

y st

aff

Incr

ease

d ris

k of

acc

iden

ts a

nd

collis

ions

Del

ay to

ope

ratio

ns

Impa

ct o

n re

crea

tiona

l boa

ting

Env

ironm

enta

l im

pact

to G

reat

B

arrie

r Ree

f, e.

g., f

rom

ac

cide

nts

and

poss

ible

spi

llage

Col

lisio

n re

sulti

ng in

dis

rupt

ion

to o

ther

shi

ppin

g op

erat

ions

Pot

entia

l ser

ious

inju

ry o

r fat

ality

Spe

ed li

mits

for v

esse

ls th

roug

h Th

e N

arro

ws

Rep

utab

le v

esse

l ope

rato

rs

Com

mun

icat

ion

betw

een

vess

els

Inte

rnat

iona

l rul

es o

f ste

erin

g

Ves

sel t

raffi

c sy

stem

Dan

gero

us g

oods

car

ried

acco

rdin

g to

the

Inte

rnat

iona

l M

ariti

me

Dan

gero

us G

oods

Cod

e

Neg

ligib

le

Boa

t stri

ke

Fast

mov

ing

vess

els

in a

reas

that

ov

erla

p w

ith th

e ha

bita

ts u

sed

by

mar

ine

turtl

es, d

ugon

g an

d in

shor

e do

lphi

n

Dea

th o

r ser

ious

inju

ry to

sp

ecie

s of

con

serv

atio

n si

gnifi

canc

e

Spe

ed li

mits

for v

esse

ls in

any

are

as id

entif

ied

whe

re

ther

e is

sig

nific

ant o

verla

p be

twee

n th

e tra

nsit

area

and

du

gong

, mar

ine

turtl

es a

nd in

shor

e do

lphi

n

Low



22.4.4 Cumulative risk levels to surrounding land uses

Considerable effort has been made to locate the gas pipeline away from sensitive receptors. The proposed gas pipeline route traverses primarily through rural areas.

Traffic and transport risks are likely to increase with concurrent construction and operation activities undertaken by multiple projects. Australia Pacific LNG will work with local authorities, the Department of Transport and Main Roads and discuss issues with other project proponents to manage traffic and transport related risks.

A fire, started for any reason by any of the proposed project activities, could spread to surrounding vegetation and become a bushfire. Bushfires threaten people, property and the environment. Controls for the prevention of bushfire, such as work procedures and maintaining clearings during construction and around surface pipeline stations are outlined in Section 22.4.2. The risk of such fires increases with concurrent construction and operation activities undertaken by multiple projects.

As the gas pipeline will be co-located with other high pressure gas pipelines for significant sections of the overall route, there will be cumulative risks as a result of the proximity to these other gas pipelines. For example, the consequence of one pipeline rupturing causing a second pipeline to rupture could potentially result in greater damage. This has been assessed in Section 22.4.6.

Further discussion of cumulative hazards and risks is presented in Volume 3 Chapter 25 – Cumulative impacts.

22.4.5 Consequence assessment overview

The purpose of the consequence assessment is to illustrate of the impacts of scenarios where there is a significant hazard related to the gas pipeline during construction, operations and decommissioning. This applies to risks which have the potential to impact persons, property or the environment by heat radiation or explosion overpressure.

All hazards, including those with the potential for catastrophic consequences, will be managed via design and ongoing safety management to reduce the likelihood of an incident to as low as reasonably practicable. While safety management procedures and emergency management plans are important with respect to a holistic approach to the management of risk, design of the gas pipeline is a critical first step with respect the overall hierarchy of controls. The hierarchy of controls including, eliminate, substitute/transfer, engineer, administration and personal protection equipment, and the risk management methodology for the control of risks based on the hierarchy of controls is presented in Volume 1 Chapter 4.

The hazards have been assessed in terms of the potential worst credible consequences of scenarios. This has been done in order to assess the outermost limits of the potential impacts. The limiting scenarios are presented and assessed to ensure that the hazards are inherently limited by design. Where it is shown that the limiting scenario meets design criteria, then other lesser potential impacts are also likely to meet design criteria.

HIPAP no. 4 has guidelines for comparing the consequences of heat flux and overpressure. These are used to identify appropriate hazard end points to be considered. Hazard end points for heat radiation levels were obtained for 4.7 kilowatts per square metre (kW/m2), 12.6kW/m2 and 23kW/m2 to assess the risk of serious injury and the risk of fatality. Similarly, hazard end points were obtained for explosion overpressure levels of seven kilopascals (kPa) and 70kPa.

Details of the consequence analysis are presented in the technical report in Volume 5 Attachment 46.



Gas pipeline incidents

The following picture illustrates the potential damage and hazards for a typical pipeline rupture in a remote location.

Natural gas has been safely handled for many years. There has never been a death or injury recorded in connection with damage to a gas pipeline in Australia (Tuft 2009). The industry is not without its incidents and accidents, but it maintains an excellent safety record as a result of the high standards adopted in the design and management standards of present day gas pipelines and facilities.

An analysis of gas pipeline incidents performed by Tuft (2009) of the Australia Pipeline incident database shows a breakdown of all damage incidents recorded. For example, the number of recorded incidents from external interference is 118, with six from construction defects, five from earthmoving, five from lightning, and three from corrosion.

In comparison, an analysis of gas pipeline incidents by the European Gas Pipeline Incident Data Group has been categorised into six different causes. External interference is similarly identified as the leading cause of gas pipeline incidents resulting in a gas leak, with an overall percentage of 49.6. Corrosion and construction defects/material failures are the next most common cause of the failures at 16.5 and 15.5% respectively.

The predominant cause of gas pipeline incidents, no matter which data source is considered, is external interference. AS 2885 contains guidelines for protecting pipeline against such threats, on the basis of the location class (i.e. additional controls for high consequence locations). For example, thicker wall pipes may be used in sensitive areas to reduce the risks of material failure, gouging, deformation and corrosion. The preliminary location classifications found when assessing the gas pipeline route, as part of the safety management study are further outlined in Volume 5 Attachment 49.

In addition to the major events identified above, gas leaks from pipelines and associated infrastructure resulting in minor fires have been known to occur in the industry. The effective response to gas leaks is a culmination of the practices equating to a good approach to process safety management. This includes the development of a gas pipeline safety management plan including emergency response plans, which outline the response to gas leaks and fires.

22.4.6 Gas pipeline hazard scenarios

The following gas pipeline hazard scenarios have been analysed:

• Rupture of gas pipeline – buried and surface

• Restricted release rates

• Rupture of adjacent gas pipeline

• Damage to third party infrastructure

• Uncontrolled detonation of explosives

• Accommodation fire

• Diesel fire involving mobile fuel tanker

• Pipeline gas explosion

• Rupture of gas pipeline through The Narrows



• Road trenches not backfilled.

Details of the modelling, consequences, likelihood and risk assessment for each scenario are presented in Volume 5 Attachment 46. The key findings from this analysis are summarised below.

Rupture of gas pipeline – buried and surface

The gas pipeline will be designed in accordance with AS 2885 to prevent a full bore rupture. Compliance with the requirements of AS 2885 and risk management controls will significantly reduce the risk of any rupture incident occurring.

This scenario has been modelled assuming a full bore guillotine rupture with uninhibited release of gas regardless of being aboveground or underground. This sort of damage could theoretically result from a severe earthquake or significant mechanical impact. This scenario has been modelled with the methodology and results presented in Volume 5 Attachment 46. The key findings are summarised below.

The model assumes a full bore rupture resulting in either a vertical or horizontal release of CSG from a 200km length of pipe. It is assumed that the failure occurs somewhere in the middle of the line so that the overall discharge is a combination of gas released from both directions, which is the worst case.

The distances to the hazard end points based on the most conservative estimates are 1279m for a thermal flux of 4.7kW/m2 (potential injury), 781m for a thermal flux of 12.6kW/m2 (chance of fatality) and 578m for a thermal flux of 23kW/m2 (likely fatality).

Restricted release rates

The maximum energy release of gas in the event of any loss of containment must be less than one gigajoule per second (GJ/s) and 10GJ/s respectively depending on the location class (Table 22.2). Energy release rates will be limited by implementing design and material selection requirements. Furthermore the properties of the gas pipeline material will resist full bore rupture.

The distances to the hazard end points for a restricted release rate of 10GJ/s based on the most conservative estimates are 206m for a thermal flux of 4.7kW/m2 (potential injury), 126m for a thermal flux of 12.6kW/m2 (chance of fatality) and 93m for a thermal flux of 23kW/m2 (likely fatality).

The distances to the hazard end points for a restricted release rate of 1GJ/s based on the most conservative estimates are 65m for a thermal flux of 4.7kW/m2 (potential injury), 40m for a thermal flux of 12.6kW/m2 (chance of fatality) and 29m for a thermal flux of 23kW/m2 (likely fatality).

Rupture of adjacent gas pipeline

This scenario has been included to acknowledge the potential hazard of co-located pipelines. The Australia Pacific LNG gas pipeline will for some distance be located in a 200 metre wide infrastructure corridor in which three other similar gas pipelines are proposed, each allocated easements 50metres wide. It is assumed that adjacent gas pipelines are of a similar size to the Australia Pacific LNG gas pipeline for the purposes of this assessment.

In theory, for two adjacent gas pipelines, if one pipe ruptures then the other pipe may also fail due to the disturbance and heat radiation. Research indicates that for two pipelines to fail they need to be located less than 25 feet (8m) apart (Leis 2002). Based on the proposed easement widths of 50m, it is unlikely that any gas pipelines will be as close as 8m. Hence, the failure of one gas pipeline is unlikely to cause an adjacent gas pipeline to rupture. However this has been modelled to illustrate the



consequences should an adjacent gas pipeline rupture occur alongside Australia Pacific LNG's gas pipeline.

The modelled distances to the hazard end points for adjacent gas pipeline rupture based on the most conservative estimates are 1,809m for a thermal flux of 4.7kW/m2 (potential injury), 1,105m for a thermal flux of 12.6kW/m2 (chance of fatality) and 818m for a thermal flux of 23kW/m2 (likely fatality).

Damage to infrastructure

The infrastructure located near the gas pipeline includes:

• Roadways, including state controlled roads and national highways

• Railway infrastructure

• Electrical power lines

• Telecommunications cables

• Other pipelines (e.g. water, tailings).

Damage to infrastructure, such as possible excavation of data cables or other pipelines, is possible during construction of the gas pipeline. However, there is unlikely to be an impact involving a catastrophic gas fire, as the gas pipeline will not contain gas until after the pipeline is completed. During operations, a gas pipeline rupture might result in an infrastructure collapse. This has been assessed in the preceding sections.

The principal controls to avoid damaging infrastructure will be outlined in construction and other safety management plans and will include those controls indicated in Table 22.3. The design of the gas pipeline and the selection of the gas pipeline route are significant first steps, which considerably reduce the risk of the likelihood of impacts and the consequences of those impacts.

Uncontrolled detonation of explosives

Explosives may be required for the construction of the gas pipeline for trenching in places along the route where conventional trench or rock breaking methods are unsuitable due to hard rock. The locations where this is most likely to occur are through rocky ranges, which are mostly in remote locations.

An uncontrolled detonation of explosives could lead to injuries or fatalities, harm to animals, or damage to surrounding property, including pipelines. Possible causes of uncontrolled detonations of explosives are:

• A vehicle engine fire as an ignition source leading to detonation perhaps due to a vehicle collision, roll-over or overheated engine.

• Misfire

• Premature detonation

• Overcharge.

Uncontrolled detonations have the potential to cause failure of adjacent existing pipelines, but this is a rare event. The risk of an uncontrolled explosion during transportation of explosives also has a remote likelihood of occurring and is a risk associated with the transportation of explosives in general.

Transportation, storage, handling and use of explosives will comply with relevant legislation. For transportation of explosives this currently includes the Explosives Act 1999, the Australian code for the



transport of explosives by road and rail and the Australian code for the transport of dangerous goods by road and rail. Complying with current legislation includes giving consideration to travel routes and separation of detonators and primary explosives away from secondary explosives. Measures taken to reduce risk during controlled blasting include the use of exclusion zones and radio silence or shielded fuses where necessary. Australia Pacific LNG will ensure that any persons involved in the transportation, storage, handling or use of explosives are suitably qualified and have the relevant licences.

Advice from relevant authorities, such as Emergency Management Queensland and the Hazardous Industries and Chemicals Branch will be sought regarding the handling and storage of explosive raw material, as well as for transportation of un-used and/or undetonated explosives before storage, handling or transportation.

Explosives will only be used in limited areas dependant on the presence of hard rock. Consequently, only minimal amounts of explosives will be transported or used, with the resultant relatively small potential impact area in the event of an uncontrolled detonation. Australia Pacific LNG's policies and practices will reduce the risk of an uncontrolled detonation of explosives during transportation and handling.

Accommodation fire

Temporary accommodation facilities will be established for work crews during the construction of the gas pipeline. These facilities will comprise of a kitchen and accommodation units. There will also be a laydown area for pipeline supplies and diesel fuel storage for refuelling light vehicles located with these facilities. The facilities will be periodically moved as the gas pipeline progresses.

While a fire in the temporary accommodation facility is possible, it is expected that these would be contained within the facility. Temporary buildings will be constructed in accordance with building code requireme

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